Tropical rainforests: Diversity begets diversity Audrey L Mayer, Stuart L Pimm  Current Biology  Volume 7, Issue 7, Pages R430-R432 (July 1997) DOI: 10.1016/S0960-9822(06)00210-7

Figure 1 Seedling survival patterns predicted by the three diversity maintenance models [1–4](a) The resource competition model predicts that seedlings will survive better in areas with similar resources to those in which the parent grows (indicated by grey shaded areas). Competition between seedlings limits the number that can survive in an area. (b) The Janzen/Connell model predicts that in the presence of enemies that concentrate near the parent tree, the greatest number of seedlings will survive at an intermediate distance from the tree. Few seeds get far from the tree, those near it get eaten. (c) The herd-immunity model predicts that the greatest number of seedling will survive in areas with the greatest number of other species. Such areas are typically far from the parent. Even enemies that attack several species of tree may not easily find their victims among a herd of inedible species. Current Biology 1997 7, R430-R432DOI: (10.1016/S0960-9822(06)00210-7)